function Mask_Login() {
	var oThis = this; 
	var id = "mask_login";
	var masklogin;
	var MaskLoginDiv;
	var flag;
		    
	this.show = function(str) {
		MaskLoginDiv = document.getElementById(id);
		if (MaskLoginDiv) {
			document.body.removeChild(MaskLoginDiv);
		} 
		MaskLoginDiv = document.createElement("DIV");
		MaskLoginDiv.id = id;
		
		var sb = new StringBuffer();
		sb.append("<div class='login-box'>");
		sb.append("<h3>用户登录</h3>");
		sb.append("<p class='login-close'><a href='javascript:void(0)' onclick='" + str + ".close();' style='cursor: hand;'>关闭</a></p>");
		sb.append("<div class='login-content'>");
		sb.append("<div class='login-b'>");
		sb.append("<div class='login-from' style='border:none;height:197px;text-align:center;'>");
		sb.append("<img src='http://image3.qqvoice.com:8181/website/image/Loading2.gif' border='0' style='margin-top:70px;' /></div></div></div></div>");	
		MaskLoginDiv.innerHTML = sb.toString(); // "";
		document.body.appendChild(MaskLoginDiv);
				
		masklogin = new MiniWin({winId : id});
		masklogin.show(masklogin);
	};
		    
	this.hide = function() {
		MaskLoginDiv.innerHTML = "";
		MaskLoginDiv.style.display = "none";
	};
	
	this.close = function () {
		flag = false;
		masklogin.hide();
	};
	
	window.onscroll = function(){
		if(MaskLoginDiv != null) {
			MaskLoginDiv.style.top = (document.documentElement.scrollTop+document.documentElement.clientHeight-500) + "px";
		}
	};
}